Judging by the raging success of diamond thieves in Hollywood movies, one might think walking away with millions in diamonds is a snap. Or at the very least, a sure thing with the right amount of planning, cunning, good looks and some sort of inside connection. In the real world, of course, slipping out with the gems takes more than two hours of careful consideration.

But such heists do work occasionally and happen pretty frequently. Every couple of years or so, a team of thieves gets away with a diamond heist. A heist is no mere robbery. It's a feat of patience and engineering that yields some of the biggest payouts in history. The weird thing is, it's hard to tell if the thieves ever see the cash, since in almost every major heist, the diamonds are never found.

Are they buried under the floorboards of an abandoned basement somewhere? Were they sold to foreign princes on the down low? Or is that diamond in the jewelry store's window the very same that was stolen from the Antwerp Diamond Center in 2003 and laundered through middlemen until it was clean enough for a legitimate jeweler to give it a second glance? We'll probably never know. But this much is for sure: The thieves who go for the high-security diamonds have guts.

In this article, we'll look at 10 of the biggest diamond heists in history, all of which went down in the last few decades. We'll see how the thieves got the goods, how much they stole and what happened in the aftermath. Each heist in this article is the stuff of legend. Are you ready for the first?

10

A Nearly Golden Getaway (1983)

Slow-motion thievery: When the thieves in this 1983 Heathrow heist discovered gold bullion instead of lighter valuables, they took it, but it took them two hours to move their haul. That's dedication.

The diamonds in this heist are something of a footnote, but the sheer perseverance of the thieves on this one makes it worthy of our list.

In 1983, thieves plotted and schemed to steal millions in cash. So what were they to do when they broke into the Brinks-MAT warehouse at Heathrow Airport to find three tons of gold bullion instead?

The robbers had inside help, thanks to the fact that one of the warehouse security guards was related to one of the criminals. With the guard's detailed knowledge of the warehouse layout and security procedures, the team of six thieves managed to raid the warehouse quickly and detain the other guards. But although they had the inside scoop, they oddly didn't know about the gold.

As a result, they didn't have a vehicle big enough to steal all of the precious metal, but they did the best they could under the circumstances. Their planned five-minute robbery wound up taking closer to two hours, as they laboriously moved bullion by hand. As an added bonus, they also found a pile of cut and uncut diamonds.

In the days after the robbery, detectives pinpointed the two-faced security guard as their prime target, and he quickly ratted out the identities of the thieves. Some of the men were caught shortly thereafter and sentenced to prison.

But the gold was never recovered. Authorities suspect that all of the gold was expertly mixed with other metals to make the bullion untraceable.

9

Machine Guns and Gems (1994)

In this snatch-and-grab, the robbers entered their target establishment firing off machine guns. Fortunately, the guns were only firing blanks, and no one was hurt.

The Carlton Hotel is a luxurious place. It's so fancy, in fact, that it has its own jewelry shop. And in 1994, that shop became the target of one of the biggest gem heists ever.

This robbery relied less on elaborate schemes and more on brute force and fear. At the shop's closing time, three masked men breezed into the store and began spraying machine gun fire.

Understandably, customers and employees panicked, and as people fled or huddled in terror, the men swept jewels into bags and made their escape with a haul valued at roughly $60 million. They were never apprehended, and the jewels were never recovered.

Yet, as police investigated the crime scene, they quickly realized one important detail -- there were no bullet holes in the walls or ceilings. The robbers had been firing blanks.

8

The Millennium Star Fake-Out (2000)

Where: Millennium Dome, London, England

When: 2000

How much: Approximately $700 million

In general, diamond heists almost always have a cinematic feel to them. There's painstaking planning, high drama and the chance that one little thing will go wrong and ruin the entire plot. But few attempted heists have the suspense and Hollywood ending of this near-record heist.

In 2000, thieves attempted to steal $700 million worth of diamonds from London's Millennium Dome. Included in the intended booty were the world-famous Millennium Star diamond, weighing in at 203.04 carats, and 12 blue diamonds, weighing a total of 118 carats, all owned by diamond conglomerate De Beers.

Stealing these gems would mean unfathomable wealth, so the criminals didn't go cheap on preparations. They came prepared with the weapons and tools to do the job right.

The thieves were heavily armed and threw gas canisters into the Dome to cover their entrance. Wearing gas masks, they ran in and smashed the display cases with sledgehammers. They were about to grab the diamonds when police officers, dressed as cleaning crew, rushed in and shut them down. The police had been tipped off before the heist and had already nabbed the speedboat that was the alleged getaway vehicle.

Even if the robbers had managed to grab the jewels and escape, they would have been distraught at their haul. The night before the attempt, authorities had replaced the real gems with fakes just to be sure they remained safe no matter the outcome of the raid.

7

Night at the Museum (2002)

One of the jewels stolen in the heist at The Hague was a wedding gift given by King William III to Queen Mary II of England.

In December 2002, thieves pulled off one of the most inexplicable diamond heists of all time. The Museon, a science museum in The Hague, Netherlands, was putting on a phenomenal diamond exhibit intended to educate the public about the gems. There were royal pieces on display, as well as jewelry lent to the Museon by other museums and private collectors.

The most valuable pieces disappeared either Sunday night or Monday morning. Because the museum is closed on Mondays, the theft went undetected for at least a day. Museum officials came in on Tuesday to find that six of the exhibit's 28 display cases were empty.

The Museon had 24-hour security guards monitoring entrances and exits, as well as 24-hour surveillance-camera footage that covered every square inch of the exhibit. The cabinets were all in a motion-detection zone, and the displays that housed the most valuable pieces (the displays the thieves emptied) were made of reinforced glass.

To this day, no one has any idea how the heist happened. Nothing showed up on the video footage, the guards never saw a thing, the motion sensors never went off and the display cabinets showed no evidence of tampering. The only signs of a break-in were a single smashed window leading into the museum -- and the empty cases. The flawlessness of the heist suggests inside information, but investigators have been unable to make any connection between the robbery and museum staff.

The Museon hasn't released details about exactly which jewels were stolen, but insiders note that a wedding gift given by King William III to Queen Mary II of England in the 1600s was among the Museon's prized pieces [source: NIS News Bulletin]. The museum eventually put a price tag of about $12 million on the robbery, but since many of the stolen pieces had historical significance, the haul is really priceless.

The gems will probably never turn up for auction because they're too famous to go unnoticed by anyone in the jewelry world. And after several years of investigation without a single lead, detectives have closed the case.

If invisible thieves can get away with $12 million in stones, what do the very visible, well-armed and dangerous types go home with? No. 6 in our countdown is a possible record breaker.

6

I'm Sorry, but That's Impossible (2003)

A thief known as "Flomenbaum" made off with approximately $28 million worth of uncut diamonds.

One of the largest diamond heists ever took place in Antwerp, Belgium, in 2003. With a confirmed value of at least $100 million, the complex crime goes down in the history books.

Antwerp is one of the two diamond capitals in the world. The other one is Dubai, in the United Arab Emirates. Eighty percent of the world's uncut gems go through Antwerp, and many of them are stored for various periods in the underground vault of the Antwerp Diamond Center building.

Of the 160 safety deposit boxes where diamond brokers leave their stones (often just overnight) while brokering deals, only 123 were emptied of their contents. The thieves had so many diamonds to carry that they were forced to leave 37 vaults unopened, and Diamond Center employees came in to find loose diamonds strewn about the vault.

At least four people had been planning the theft for years. They rented office space in the building in 2000, analyzed the alarm system and learned how to bypass it. They also obtained keys to the vault and made copies. On the day of the break-in, they recorded over the security cameras and inserted fake tapes into the surveillance system to cover their movements. All of these coordinated actions suggest an inside job, and as it turns out, it was.

The gang was identified as a group known as the School of Turin -- a "brilliant" group of thieves that never uses violence. One member is known as the King of Thieves, and insiders refer to another one as the Magician with the Keys [source: BBC News]. The investigation accordingly led to Italy, and most of the group were arrested by Antwerp police working in conjunction with Italian law enforcement. One of the thieves had left his DNA on a half-eaten sandwich among diamond-carrying bags dumped in a ditch near the crime scene. Another thief's DNA was found in the vault. He had acted as a diamond merchant for years, apparently storing stones in the Diamond Center, and had somehow passed all of the Center's background checks.

Most of the thieves are in prison, but the $100 million worth of diamonds and other gems they stole have never been found. Italian police discovered some of the loot in a vault in Italy and photographed the items for confirmation, but by the time Antwerp authorities arrived to collect the stolen stones, they were gone -- removed from yet another supposedly secure location.

The next one on our list isn't the biggest haul, but it is quite possibly the most impressive. How can you beat the long con?

5

Follow that Truck! (2005)

Where: Schiphol Airport, Amsterdam

When: Feb. 25, 2005

How much: Possibly $118 million (unconfirmed)

This one makes the list for its sheer dollar amount. Because many of the stolen stones were uncut (and uncut stones are difficult to put a definite value on), an absolute figure has never been confirmed. But if the roughly $118 million estimate is correct, the Amsterdam airport heist is the largest diamond heist ever.

The heist was more like something out of a gangster film than a sophisticated plot like "Ocean's Thirteen" -- it was a truck hijacking, plain and simple. Two weeks before the heist, the thieves did a test run in a stolen KLM Cargo truck. At least one of the thieves broke into the freight area at Schiphol airport and made sure everything was in order. Then on Feb. 25, wearing stolen KLM uniforms and driving yet another stolen KLM truck, the gang drove right up to a truck carrying diamonds intended for a flight to Antwerp. With plenty of people watching, the team forced the drivers out of the truck at gunpoint, had them lie facedown on the ground, hopped into the truck and drove away.

Since the thieves obviously knew which truck to target and how to get their hands on KLM uniforms and a KLM truck (twice), police suspected inside help. Diamond merchants who lost millions in stones blame the airport's poor security. And the heist was actually the second time in six months that the cargo terminal had been infiltrated [source: BBC News]. Investigators haven't recovered the stones.

It's likely the diamonds stolen in the next entry on our list will never show up again, either. They're too famous.

4

A Chocolate for Your Key? (2007)

Where: ABN Amro Bank, Antwerp, Belgium

When: March 2, 3 or 4, 2007

How much: Approximately $28 million

No one knows his real name, but the staff members at the ABN Amro bank in Antwerp's diamond district knew him as Carlos Hector Flomenbaum. Flomenbaum billed himself as a successful businessman, and he'd frequented the bank for at least a year. The bank's employees loved the guy, described as a gray-haired man between the ages of 55 and 60, speaking American-accented English and brandishing an Argentinean passport. He brought the bank's workers boxes of chocolates, talked to them about non-diamond-related matters and ultimately won their trust to the extent that he was given VIP access to the vault.

At the bank, certain customers are given keys so they can access their diamonds at odd hours. Flomenbaum became one of these trusted key holders, and sometime between March 2 and March 5, 2007, he let himself into the vault and walked out the front door with 120,000 carats of diamonds.

The ABN Amro bank has a $2 million security system. But "Flomenbaum" never had to deal with that. He used his pass card to get into the vault, went straight for the area that he knew held uncut diamonds and emptied five of the deposit boxes. Antwerp's diamond merchants were stunned. It's still unclear how a man with what turned out to be a stolen passport could have passed the bank's background checks.

Among the stolen gems were 41 blue and two extremely rare green stones. In all, the haul was worth about $28 million.

3

The Italian Job (2008)

Thieves made off with millions of dollars worth of diamonds, rubies and gold from the Damiani showroom in Milan.

This next one begins with a woman in Milan complaining to police at least once about early-morning noise in her neighborhood. Because there was a construction project going on nearby, nothing came from her complaints; the police (and everyone else) figured that the noise was coming from the workmen. No one considered that the woman lived practically next door to the world-famous Damiani jewelry showroom.

Damiani's building was secure, with a high-tech alarm system and an armed guard at the front door. None of that really mattered, though, since the thieves had been drilling a hole every morning through the 4-foot (1.2-meter) wall that separated the showroom basement from the basement next door.

Their timing was almost perfect. The store had been preparing for a private showing, so there were no customers in the showroom -- just staff members who could open the vault. The thieves wore fake or stolen police uniforms and popped up in the showroom through an inner, unguarded entrance, at 10 a.m. Unarmed, and apparently relying on surprise and disguise, they asked to see certain store records and then pounced, tying and gagging the staff. They temporarily untied one employee to open the safe. The operation took about a half hour, netting about $20 million in diamonds, rubies and gold [source: NY Post].

So what was the only flaw in such a grand heist? The thieves would have made off with much more had it not been Oscar time. Some of the most valuable pieces were out on loan to Hollywood's stars, including Oscar winner Tilda Swinton, who wore Damiani's "Sahara Bracelet," bearing 1,865 diamonds totaling more than 47 carats [source: Reuters]. The investigation is ongoing. Police suspect an inside job -- the timing was just too perfect.

2

Drag Queen Diamonds (2008)

Some of the thieves in this heist dressed as women to disguise themselves.

As robberies go, this downtown Paris heist was executed in a relatively genteel, civilized manner. Perhaps that's because it was conducted by women -- or at least, men dressed to look like women.

On Dec. 4, 2008, four gun-toting robbers entered the Harry Winston store and made off with roughly $107 million worth of jewelry and diamonds. That's just short of the record-setting mammoth haul of $127 million in diamonds taken in Antwerp in 2003.

At about 5:30 p.m., the four men -- at least some of whom had donned female clothing and wigs -- sauntered casually into the Winston store, which was right down the street from a Parisian police station. They immediately went into action, menacing employees and customers with handguns.

There's no doubt that the robbers were already familiar with the store and its employees, who they allegedly called by their first names. They also knew the location of secret safes located throughout the store.

Within 20 minutes, the still-at-large criminals had cleared out much of the store's stock, including diamond rings, watches, necklaces and much more. Then, they calmly and quietly exited the store, drove away and were never seen again.

They had a plan, great disguises and a clean getaway. But this next set of diamond-crazed criminals left behind a clue that led to their eventual arrests.

1

From Prosthetics to Prison (2008)

Where: Graff Diamonds, London, England

When: Aug. 6, 2009

How much: Approximately $65 million

At just before 5 p.m., two men wearing suits entered the store. They looked the part of just about any other wealthy men looking to buy expensive gems and jewelry, but really, their looks said nothing about them at all.

That's because they had visited a professional makeup artist, who altered their skin color, applied prosthetics to change the shapes of their faces and ultimately made them appear to be entirely different people.

They put their altered appearances to use by waltzing brazenly into the store, unveiling handguns and threatening employees, who hurriedly unlocked display cases. In all, the men made off with more than 40 pieces of jewelry valued at a whopping $65 million.

They exited the store, fired at least one gunshot to frighten and confuse witnesses, and then drove away. A short while later, they switched vehicles (and fired another shot for good measure) and sped away from the scene.

But the robbers committed a forehead-slapping blunder. During their hasty escape, they left a cell phone in one of their getaway cars. Police used numbers on the phone to track down the men, and on Aug. 20, authorities charged Solomon Beyene and Craig Calderwood with conspiracy to commit robbery and attempted murder, among other offenses.

From there, the police made more and more arrests, totaling 10 men in all. And although they apprehended the perpetrators, they never recovered the stolen merchandise.

So whether the thieves are using a sledgehammer or a really sincere smile, there are at least a couple of things the big diamond heists have in common. First, a successful heist typically requires inside help. After all, we're talking about the most highly guarded carbon in the world. And second, while the thieves may be caught, the diamonds are almost never found.

Learn more about diamonds, diamond thieves and other related topics on the next page.